نتایج جستجو برای: organic solvent free

تعداد نتایج: 743377  

Journal: :Chemical communications 2013
Dibakar Kumar Maiti Arindam Banerjee

A peptide based two component white light emitting system has been designed and developed on the basis of a co-assembly of a PDI containing peptide system as an acceptor and a stilbene containing peptide system as a donor in organic solvents.

Journal: :Chemical communications 2006
Sanzhong Luo Xueling Mi Song Liu Hui Xu Jin-Pei Cheng

A surfactant-type asymmetric organocatalyst (STAO) catalyzed highly efficient Michael addition to nitroalkenes with high stereoselectivities in water without using any organic solvents or additional additives.

Journal: :Chemical communications 2016
Krunoslav Užarević Timothy C Wang Su-Young Moon Athena M Fidelli Joseph T Hupp Omar K Farha Tomislav Friščić

We develop the first mechanochemical and solvent-free routes for zirconium metal-organic frameworks, making the frameworks UiO-66 and UiO-66-NH2 accessible on the gram scale without strong acids, high temperatures or excess reactants. The frameworks form either by milling, or spontaneous self-assembly by simply exposing solid mixtures of reactants to organic vapour. The generated frameworks exh...

2017
Razieh Pourahmad Jaktaji Farzaneh Zargampoor

AcrAB-TolC is a major efflux pump in Escherichia coli. It was reported that tolC is overexpressed and involves in improving the organic solvent tolerance level in Escherichia colimarR mutants that are resistant to several antibiotics, such as ciprofloxacin. Low and intermediate levels resistance did not improve organic solvent tolerance. Thus, it was decided to measure tolC expression and organ...

2015
MANRAJ KAUR RAKESH NARANG SURENDRA KUMAR NAYAK

Lithium perchlorate is a Lewis acid catalyst which activates a large number of organic reactions providing high yields with enhanced reaction rates. Moreover, it makes some of the reactions possible to proceed under solvent-free conditions which is an important aspect for the development of green chemistry. This paper canvasses the chemical literature on lithium perchlorate as a catalyst for or...

Journal: :iranian journal of catalysis 0
mona hosseini-sarvari department of chemistry, shiraz university, shiraz 71454, i.r. iran. sepideh najafvand-derikvandi department of chemistry, shiraz university, shiraz 71454, i.r. iran.

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

Journal: :iranian journal of catalysis 2011
hossein naeimi abdol hamid raesi mohsen moradian

the use of methanesulfonic acid as a brønsted acid for direct ortho-acylation of phenols and naphthols proves to be a convenient, more general and direct route to various hydroxyaryl ketones. the route is regioselective, leading to ortho c-acylated products in satisfactory to high yields in most cases. the solvent free reactions described below exhibited environmentally benign in terms of faste...

Journal: :iranian chemical communication 2013
seyyedeh fatemeh hojatia kobra nikoofar zahra etemadifara

a condensation of various isatins with indole derivatives has been carried out in the presence of 1,3-dibromo-5,5-dimethylhydantoin (dbdmh) as catalyst at 50 °c in ethanol in order to form 3,3-bis(indolyl) oxindoles. the products were obtained within 20-90 min by 70-96% yields. the efficacy of the procedure has been confirmed by catalyzing the condensation reaction of pyrrole which was used as ...

Journal: :iranian chemical communication 2014
sobhan rezayati zahra erfani saman rezayati rahimeh hajinasiri marzieh rekavandi

1,1-diacetates(acylals) were prepared by direct condensation of various aldehydes with acetic anhydride using dipyridine cobalt chloride (copy2cl2) as an efficient and green catalyst under solvent-free conditions at room temperature. the important features of this catalyst method are that the catalyst is solid, stable at high temperatures, soluble in water, stable in air, immiscible in common o...

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